Income Taxes (Detail) - Rollforward of Unrecognized Tax Benefits - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance		$ 912	$ 279	$ 0
Additions for tax positions relating to the current year		480	635	279
Additions for tax positions relating to prior years		37	0	0
Reductions for tax positions relating to prior years		(21)	(2)	0
Ending balance		1,408	912	279
Interest and penalties not included above:
Interest expense, net of tax effect, and penalties	[1]	20	4	0
Accrued interest and penalties, net of tax effect, at end of year	[1]	$ 24	$ 4	$ 0

[1] Included in income tax expense in the Consolidated Statements of Income.